package case1;

import case1.core.observer.QuackObservable;

/**
 * description:
 * 呱呱叫
 * @author Yuanml
 * @date 2020/11/1 上午9:35
 **/
public interface Quackable extends QuackObservable {
    /**
     * duck quack
     */
    void quack();
}
